mirror of
https://gitee.com/coder-xiaomo/leetcode-problemset
synced 2025-11-04 11:43:12 +08:00
41 lines
1.8 KiB
HTML
41 lines
1.8 KiB
HTML
<p>You are given a <strong>0-indexed</strong> string <code>blocks</code> of length <code>n</code>, where <code>blocks[i]</code> is either <code>'W'</code> or <code>'B'</code>, representing the color of the <code>i<sup>th</sup></code> block. The characters <code>'W'</code> and <code>'B'</code> denote the colors white and black, respectively.</p>
|
|
|
|
<p>You are also given an integer <code>k</code>, which is the desired number of <strong>consecutive</strong> black blocks.</p>
|
|
|
|
<p>In one operation, you can <strong>recolor</strong> a white block such that it becomes a black block.</p>
|
|
|
|
<p>Return<em> the <strong>minimum</strong> number of operations needed such that there is at least <strong>one</strong> occurrence of </em><code>k</code><em> consecutive black blocks.</em></p>
|
|
|
|
<p> </p>
|
|
<p><strong>Example 1:</strong></p>
|
|
|
|
<pre>
|
|
<strong>Input:</strong> blocks = "WBBWWBBWBW", k = 7
|
|
<strong>Output:</strong> 3
|
|
<strong>Explanation:</strong>
|
|
One way to achieve 7 consecutive black blocks is to recolor the 0th, 3rd, and 4th blocks
|
|
so that blocks = "BBBBBBBWBW".
|
|
It can be shown that there is no way to achieve 7 consecutive black blocks in less than 3 operations.
|
|
Therefore, we return 3.
|
|
</pre>
|
|
|
|
<p><strong>Example 2:</strong></p>
|
|
|
|
<pre>
|
|
<strong>Input:</strong> blocks = "WBWBBBW", k = 2
|
|
<strong>Output:</strong> 0
|
|
<strong>Explanation:</strong>
|
|
No changes need to be made, since 2 consecutive black blocks already exist.
|
|
Therefore, we return 0.
|
|
</pre>
|
|
|
|
<p> </p>
|
|
<p><strong>Constraints:</strong></p>
|
|
|
|
<ul>
|
|
<li><code>n == blocks.length</code></li>
|
|
<li><code>1 <= n <= 100</code></li>
|
|
<li><code>blocks[i]</code> is either <code>'W'</code> or <code>'B'</code>.</li>
|
|
<li><code>1 <= k <= n</code></li>
|
|
</ul>
|